[FFmpeg-devel] [PATCH] swscale: Remove duplicated code

[Michael Niedermayer]

On Mon, Mar 25, 2019 at 12:36:24PM +0100, Hendrik Leppkes wrote:
> On Mon, Mar 25, 2019 at 11:35 AM Lauri Kasanen <cand at gmx.com> wrote:
> >
> > On Mon, 25 Mar 2019 11:17:38 +0100
> > Michael Niedermayer <michael at niedermayer.cc> wrote:
> >
> > > On Sun, Mar 24, 2019 at 01:04:51PM +0200, Lauri Kasanen wrote:
> > > > In this function, the exact same clamping happens both in the if and unconditionally.
> > > >
> > > > Signed-off-by: Lauri Kasanen <cand at gmx.com>
> > > > ---
> > > >  libswscale/output.c | 14 --------------
> > > >  1 file changed, 14 deletions(-)
> > >
> > > The removed code is the one that should stay, the other should be
> > > removed.
> > > one check for a rarely true condition should be faster than 4 checks
> >
> > Yes, I thought so too, but the commit that added the unconditional code
> > says it fixes a bug...
> >
> 
> Could it overflow so high that other bits then the one being checked
> for are set? 

in realistic cases this should not happen. It may be possible
to construct a case with crafted scale parameters where this happens


> Perhaps another bit pattern with more high bits set would
> solve that.

yes, actually i thought we did use a different pattern ...

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Observe your enemies, for they first find out your faults. -- Antisthenes
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